Circuits integrated on one chip which have a separate transmission and reception path for radio signals are called transceivers. Transceivers can be divided into two different classes depending on the area of application. Transceivers which are able to transmit radio signals and simultaneously to receive radio signals from a second transmitter are called “full duplex” transceivers. The other class does not support a full duplex mode of operation, but rather can either just transmit or receive.
An example of such a transceiver is shown in FIG. 9. In this case, the area E contains part of the reception path, the area S contains part of the transmission path. For transmitting data, an oscillator device VCO (voltage controlled oscillator) switches to a frequency fTX. A power amplifier PA amplifies the modulated signal and transmits it using an antenna ANT in the transmission path. When data are to be received, the oscillator device VCO switches to another, second frequency fRx and feeds this signal as a LO input into a device for frequency conversion MIXER in the reception path. The mixing device MIXER in the reception path E converts a received signal amplified by an amplifier LNA to an intermediate frequency FIF. The converted signal is filtered and is supplied to an IQ demodulator for further processing. The need to switch the oscillator device VCO to different frequencies in order to transmit or receive data means that it is not possible to transmit and receive simultaneously.
It is therefore an object of the invention to provide an arrangement and a method for transmitting and receiving radio signals simultaneously.